The Tylers, this time Anderson, are struggling again as Rockies fall out of first place in the NL West

Kyle Seager’s 433-foot home run in the second inning Tuesday night landed in the corner of the visitor’s bullpen at Coors Field, over the center-field wall and into the long, evening shadows. Robinson Cano’s homer in the seventh burrowed within feet of the same spot — as if the Seattle sluggers were playing a game of hardball H-O-R-S-E.

And in losing a second consecutive game for the first time in more than two weeks, the Rockies got belted from multiple angles. The Mariners’ runaway 10-4 victory to sweep a quickie two-game series in the first half of a home-and-away set turned into a hard break on the Rockies’ runaway momentum.

For the first time since May 3, the Rockies fell out of first place in the National League West. The Los Angeles Dodgers, who rallied for a 9-4 victory over the Cardinals in St. Louis, took over the top spot.

“Starting pitching is a critical part of a team’s success,” Colorado manager Bud Black said. “These two games, back to back, we have not ‘starting pitched’ well. That’s the big reason why we lost these two games.”

The Rockies since the middle of April have been baseball’s darlings of statistical quirks, the outliers at altitude. They have spent just three days out of first place in a division they have never won. But they traveled to Washington state late Tuesday night with ground to regain.

Some anxiety surfaced before they left. Tyler Anderson’s five sideways innings Tuesday — he gave up six runs on 11 hits in a five-inning outburst that included Seager’s longball — became the second worrisome start from the senior members of Colorado’s rotation. Fellow 27-year-old Tyler Chatwood on Monday allowed six runs on seven hits in an even briefer outing.

“There really wasn’t much command with anything,” Anderson said.

The Tylers have yet to catch up to their rookie counterparts. Anderson and Chatwood, combined, carry a 5.43 ERA this season. Colorado’s first-year arms — Antonio Senzatela, Kyle Freeland and German Marquez — have a collective 3.42 ERA. And another excelling rookie, Jeff Hoffman, is lying in wait at Triple-A Albuquerque.

Anderson’s issues pushed him suddenly off course. He entered Tuesday with a 2.55 ERA in three previous May starts, including a one-run effort over a season-high seven innings last week at Philadelphia.

Against the Mariners, though, after he walked Nelson Cruz to lead off the second inning, Anderson elevated a 91 mph fastball at the top of the zone that Seager crushed to center field. Then Mike Zunino’s double down the left-field line was bobbled by Ian Desmond in the corner and Guillermo Heredia scored.

“Lots of things were up in the zone. I had a hard time throwing, so I had to go middle and hope for the best,” Anderson said. “But balls in the middle will get hurt a lot.”

The third was equally hurtful. Ben Gamel and Seager looped back-to-back doubles to right field. Seager’s scored two runs. Heredia knocked in another. And the M’s had a 6-0 lead before the Rockies found their first hit. Anderson got yanked after five innings. Cano’s leadoff homer in the seventh off reliever Mike Dunn only compounded the chase.

“Just goes to show you,” Anderson said, “no matter what you do, how good or bad you think you are, you have to keep making pitches. And quality pitches is how you get guys out. You don’t get guys out throwing balls down the middle. Hitters are too good.”

By the time Carlos Gonzalez doubled to start the fifth inning and DJ LeMahieu blooped in two runs, the Rockies were deep in a deficit. They scratched just three hits off Seattle veteran lefty Ariel Miranda. The Mariners, a fourth-place team in the AL West and just 9-20 on the road before their visit to Denver, tacked on three more runs in the ninth off recently recalled reliever Carlos Estevez.

The Rockies’ three-armed rookie rotation returns Wednesday night at Safeco Field in Seattle, with Senzatela throwing against the Mariners to start two games there. Freeland follows. Marquez will pitch Friday at San Diego. The kids have a house to put in order.

“Arguably the most important player on the field is the starting pitcher,” Black said. “If he pitches well, we have a really good chance to win. It is critical.”